Sulphur fire (Lake County): 2,207 acres, 162 structures destroyed; referred to the District Attorney. Fire ignited when a PG&E power pole failed, causing power lines and equipment to contact the ground.

Cal Fire investigators said Friday that equipment owned and operated by PG&E ignited 12 wildfires that raged in hot, dry weather and high winds across Northern California in October, charring hundreds of square miles in Sonoma County and beyond, destroying thousands of structures and killing 18 people.

The utility was in violation of state code on eight of those fires, failing to clear brush around its lines and properly maintain its power equipment, according to state fire investigators.

Cal Fire found violations in the Norrbom, Partrick, Pythian, Adobe and Pocket fires that burned in Sonoma and Napa counties; the Atlas fire in Napa County; the Sulphur fire in Lake County; and the Blue fire in Humboldt County. The agency forwarded its reports to district attorneys in those jurisdictions for review.

In the other four fires — the Redwood in Mendocino County, Cherokee in Butte County and the 37 and Nuns fires in Sonoma County — flames were ignited by power equipment but investigators found no evidence the utility company had violated state regulations.

The report is the latest set of findings from state fire investigators examining the causes of dozens of fires that burned more than 245,000 acres across Northern California in October, destroyed nearly 6,200 homes and killed 44 people.

The probes have now found evidence in 11 of the 16 fires that PG&E had allegedly violated state codes designed, in part, to prevent fires by keeping tree limbs and other vegetation away from power lines.

Investigators have not yet released their determination on the Tubbs fire — the state’s most destructive — that burned from Calistoga into Santa Rosa, killing 22 people and destroying more than 4,000 homes, most of them in Santa Rosa.

PG&E issued a statement that “we look forward to the opportunity to carefully review the Cal Fire reports to understand the agency’s perspectives.”

“Based on the information we have so far,” the company said, “we continue to believe our overall programs met our state’s high standards.”

The utility giant has been fighting for its future in Sacramento, lobbying lawmakers to change the state Constitution to remove a legal doctrine that requires the utility to pay for private property damage even if it isn’t found to have been negligent.

Called inverse condemnation, the legal safeguard ensures private property owners are compensated for damage related to public infrastructure, including private utility and telecommunications equipment, regardless of fault.

Patrick McCallum, a Sacramento lobbyist whose Santa Rosa home was destroyed in the Tubbs fire, criticized PG&E’s attempt to diminish its potential financial liabilities related to the fires.

He heads a coalition of displaced residents and trial attorneys called “Up From the Ashes.”

“PG&E has been trying to duck responsibility for the fires, blaming everything from climate change to local fire departments and the state’s liability laws,” McCallum said in an email. “Cal Fire’s report puts the blame where it belongs — squarely on PG&E, confirming it was responsible for many of the fires that devastated so many lives.”

Beyond the Tubbs fire, it’s unclear how many more reports remain for Cal Fire to complete. Spokesman Scott McLean said he didn’t know the number of outstanding investigations. The remaining four Northern California fire deaths were in a Yuba County blaze whose cause has not yet been determined by Cal Fire. State firefighters responded to more than 170 fires in October, but many of those were small, McLean said.

Cal Fire findings on 12 Northern California wildfires

Those referred to the District Attorney indicate Cal Fire determined PG&E was in violation of state code.

Sulphur fire (Lake County): 2,207 acres, 162 structures destroyed; referred to the District Attorney. Fire ignited when a PG&E power pole failed, causing power lines and equipment to contact the ground.

“They are very meticulous and they’re very determined to get to the cause and get that information to the public,” he said.

State Sen. Bill Dodd, D-Napa, called the alleged violations of state code “disappointing and deeply concerning.”

“It’s inexcusable, and it can’t be allowed to happen again,” he said in a statement.

Dodd called on PG&E, other utilities in California and the state Public Utilities Commission “to step up and ensure they are meeting their legal obligations to maintain power lines in a safe manner.”

State Sen. Mike McGuire, D-Healdsburg, praised Cal Fire for an “extensive and thoughtful investigative process” and called the report a “step forward in getting the answers communities deserve.”

“I’ve always said if PG&E or any other company is found negligent, they should be responsible for the damages caused by this devastating blaze,” McGuire said.

Sonoma County Board of Supervisors Chairman James Gore said the results were not surprising given “reports all over the region of trees going into lines and then sparking.” Gore called for change from the utility, which the county is suing because of the fires. But he cautioned against going too far.

“Anything we do with PG&E going forward has to be about this not happening again, not just trying to extract blood money to pay for impacts,” he said.

The alleged violations of state law now must be considered by county prosecutors, including Sonoma County District Attorney Jill Ravitch.

In an interview Friday, Ravitch said her staff is working with counterparts in Napa and Lake counties, as well as in the state Attorney General’s Office, to “review the investigation and determine what steps will be taken.”

In its statement, PG&E noted it prunes or removes approximately 1.4 million trees annually as part of an “industry-leading vegetation management program.” The company maintained it also meets or exceeds state requirements for managing patrols and inspections of more than 2 million power poles it owns.

Since 2014, the utility said, it has increased daily aerial fire detection patrols during high fire season, added foot and aerial patrols of power lines in high fire-risk areas and removed “hundreds of thousands of dead or dying trees” weakened by drought and bark beetle infestations.

Friday’s release underscored the public’s interest in learning the cause of the historically destructive Tubbs fire, which leveled Santa Rosa’s Fountaingrove and Coffey Park neighborhoods. The first Sonoma County couple known to have sued PG&E after the blazes — one of now hundreds of lawsuits seeking damages from the utility after the firestorm — had their home destroyed in Coffey Park.

Late last year, the state Public Utilities Commission posted reports online of at least four wildfires that began in October at or near addresses where damaged PG&E equipment was discovered. Three of the blazes — the Atlas, Partrick and Nuns fires — were among those listed in Friday’s report with their causes tied to utility equipment. The fourth was the Tubbs fire, for which regulators reported that damaged utility equipment had been found at a property in Calistoga near that fire’s origin.

However, PG&E in November raised the possibility that power equipment “owned, installed and maintained by a third party” at that same Calistoga address might be responsible for the Tubbs fire and not the utility’s equipment.

Santa Rosa Mayor Chris Coursey said Cal Fire findings were “what everyone has suspected all along” and he will be surprised if the Tubbs fire investigation concludes any differently.

“We were obviously affected by all kinds of fires last October, but the Tubbs fire did the vast majority of the damage within city limits,” Coursey said. “I’m really anxious to see what the determination is on that fire.”

PG&E has filed claims arguing Sonoma County and the city may share responsibility for the damage if PG&E is found liable for the fires.

Early on in the firefight, PG&E equipment seemed a likely ignition source for the fires.

With crews still battling to contain the infernos, more than two dozen members of Cal Fire’s investigative branch were deployed to help pinpoint the origins of each fire and start trying to determine what caused them. They examined burn patterns and physical evidence, interviewed witnesses including 911 callers, and reviewed dispatch records.

They also examined the utility equipment at the origin areas of many of the fires. Last year, PG&E notified the Public Utilities Commission that investigators seized the company’s equipment, including damaged power poles and downed lines near the origins of several wildfires.

On May 25, Cal Fire released a first set of investigations into some of the smaller fires that broke out in October in Butte and Nevada counties, saying those fires were all caused by trees or branches falling into PG&E power lines.

In three of those cases — the Lobo and McCourtney fires in Nevada County and the Honey fire in Butte County — investigators found PG&E was responsible and alleged the utility violated state code requiring that utilities maintain adequate clearance between power lines and trees or other vegetation, and sent those reports to District Attorneys for review.

The investigations suggest the utility giant could face significant financial liability for the firestorm, which was fueled by winds gusting up to 65 mph late Oct. 8 and early Oct. 9.

The investor-owned utility faces hundreds of lawsuits from people who lost homes or family members in the fires, in addition to lawsuits lodged by the counties of Sonoma, Lake, Mendocino and Napa over its alleged role in the historic fires.

PG&E has $800 million in liability insurance, but insurance claims from the fires now total nearly $10 billion.

Cal Fire’s findings don’t provide a sure path to victory for the burned-out residents suing PG&E, but the findings bolster arguments that PG&E is to blame for at least some of the damage. The lawsuits claim PG&E is responsible because it failed to properly maintain its power lines and didn’t prepare for high winds, which were predicted days in advance. PG&E lawyers have argued the fires were a result of multiple unprecedented weather impacts, including a multiyear drought.

Santa Rosa attorney Noreen Evans, who is on a legal team representing about 1,300 clients suing PG&E over the fires, said Cal Fire’s announcement validates what lawyers suing the utility have known for “quite some time.” And she found it noteworthy that the Atlas fire had been referred to the Napa County District Attorney’s office, calling it “really serious,” given that six people died in that fire.

Cal Fire’s findings provide a framework for how to argue the case in court, said John Fiske, a lawyer representing burned-out residents as well as Sonoma, Napa and Mendocino counties in their litigation against PG&E.

Fiske said plaintiffs intend to prove PG&E was negligent even in cases where Cal Fire found no state code violation by arguing the utility company should have maintained its equipment and developed sufficient plans for protecting against fires during predicted windstorm events.

“Just because they’re not in violation of a statute doesn’t mean they weren’t negligent,” Fiske said.